First efficient synthesis of SF₅-substituted pyrrolidines using 1,3-dipolar cycloaddition of azomethine ylides with pentafluorosulfanyl-substituted acrylic esters and amides

Abstract

A single step procedure for the efficient synthesis of di‐, tri‐, and tetrasubstituted pentafluorosulfanylated pyrrolidines is developed.

Catalytic Enantioselective Synthesis of Highly Functionalized Pentafluorosulfanylated Pyrrolidines

“…The (E)-3-pentafluorosulfanylprop-2-enol was purchased from Synquest Laboratories and was used without further purification. [16] (E)-3-pentafluorosulfanylprop-2-enoic acid [20] and SF 5 -esters 1a and 1b [21] were prepared according to the literature. Ligand L 3 was prepared according to the literature.…”

“…[12] Using as imilar approach,Z hang developed ac opper-catalyzed exo-selective [3+ +2] cycloaddition of azomethine ylides with b-CF 3 b,b-disubstitutede nones by using (S)-MeO-DTBM-Biphep as ac hiral catalyst (Scheme 1, Eq. [16] This approach needs long reactiont imes and am ixture of regioisomers was generally observed (from 1:1t o2:1). [13] Subsequently,o ne of us described the synthesis of aromatic amide-derived nonbiaryl atropisomers (Xing-Phos in particular) and its application to as ilver-catalyzed [3+ +2] cycloaddition of aldiminoesters to nitroalkenes or a,b-unsaturated ketones with high diastereo-and enantioselectivities (Scheme 1, Eq.…”

A Unique (3+2) Annulation Reaction between Meldrum's Acid and Nitrones: Mechanistic Insight by ESI‐IMS‐MS and DFT Studies

“…This interaction likely enhances the electrophilic character of nitrone 2a and promotes the subsequent nucleophilic addition reactiono fe nolate 4a.T he formation of the CÀCb ond takes place through transition state TS1 and protonation of nitrone 2a,w hich occur as as ingle step (with an overall activation barriero f14.6 kcal mol À1 )t oa fford intermediate Int2.T his compound then undergoes cyclization by the formation of aC ÀOb ond (see dashed line in TS2)a nd is associated to as econd proton transfer from the hydroxylamine moiety to trimethylamine, along with am oderate activation barrier(11.9 kcal mol À1 ). [18] Accordingly,t he ion of m/z = 354 seen by ESI-MSl ikely refers to cyclic structure 11C (see Scheme 2). Accordingly,a na cetone molecule can be exothermically eliminated from Int3 by relevantC ÀOb ond breaking at al ow energetic cost (6.4 kcal mol À1 ), and this leads to relativelys table carboxylate intermediate Int4.T he activation barrier TS4 (26.0 kcal mol À1 )f or the subsequent decarboxylation reactionp roviding intermediate Int5 is markedly higher than that for the nucleophilic addition step and that for the cyclization step( Int1 to Int2 to Int3).…”

Nine questions on energy decomposition analysis

“…In such cases, even if very accurate and meaningful EDAs are obtained for the electronic part, the thermodynamic contributions remained an issue, notably for condensed phases. From this point of view, EDAs cannot guide us for selecting the most relevant physicochemical properties …”

“…From this point of view, EDAs cannot guide us for selecting the most relevant physicochemical properties. [140] Paul W. Ayers I often use the following quote from Willard van Orman Quine, [141] [1953], "Our acceptance of an ontology is, I think, similar in principle to our acceptance of a scientific theory, say a system of physics; we adopt, at least insofar as we are reasonable, the simplest conceptual scheme into which the disordered fragments of raw experience can be fitted and arranged. "…”